Small electric steering engine with large reduction ratio

Abstract

The invention relates to the technical field of steering engines, in particular to a small-sized large-reduction-ratio electric steering engine which comprises a shell base, a rear shell and a front shell, and the rear shell and the front shell are installed on the shell base. A harmonic reducer and a bevel gear transmission pair are arranged in a cavity defined by the shell base and the rear shell. A straight gear transmission pair is arranged in a cavity defined by the shell base and the front shell. A brushless direct current motor is installed on the outer wall of the rear shell, and power of the brushless direct current motor is transmitted to the straight gear transmission pair through the bevel gear transmission pair and the harmonic reducer in sequence. The bevel gear transmission pair, the harmonic reducer and the straight gear transmission pair are used for speed reduction, and the harmonic reducer has a large reduction ratio range, so that the requirements of miniaturization and light weight of the electric steering engine are met.

Description

Technical Field

[0001] The present invention relates to the technical field of steering gears, and particularly to a small-sized electric steering gear with a large reduction ratio. Background Art

[0002] The electric steering gear is an important control and execution component in torpedoes. With the continuous development of torpedo technology, it is required that the steering gear be smaller, lighter, and more integrated, and at the same time, it needs to have high overload capacity, a large reduction ratio, and high-precision output.

[0003] Regarding steering gear technology, there are currently many related patent applications. For example, the patent application with the publication number CN113639595A discloses a steering gear system, including a deployment steering gear and an adjustment steering gear. The output end of the deployment steering gear is connected to the adjustment steering gear to drive the angle change of the adjustment steering gear. A steering board is connected to the adjustment steering gear, and the adjustment steering gear drives the angle change of the steering board. This steering gear system can realize the deployment and angle adjustment of the steering board, and can achieve two-degree-of-freedom adjustment in the application fields of torpedoes or mines.

[0004] However, for the steering gear structure in the above-mentioned prior art, a multi-stage gear reduction mechanism is used for torque output, resulting in a large structure of the entire electric steering gear and being unable to meet the requirements of miniaturization and lightweight of the electric steering gear. Summary of the Invention

[0005] The main purpose of the present invention is to propose a small-sized electric steering gear with a large reduction ratio, aiming to solve the above technical problems.

[0006] To achieve the above purpose, the present invention proposes a small-sized electric steering gear with a large reduction ratio, including a housing base, a rear housing, and a front housing mounted on the housing base; a harmonic reducer and a bevel gear transmission pair are arranged in the cavity formed by the housing base and the rear housing; a spur gear transmission pair is arranged in the cavity formed by the housing base and the front housing; a brushless DC motor is installed on the outer wall of the rear housing, and the power of the brushless DC motor is sequentially transmitted to the spur gear transmission pair through the bevel gear transmission pair and the harmonic reducer.

[0007] Preferably, the bevel gear transmission pair includes a driving bevel gear and a driven bevel gear that mesh with each other; the spur gear transmission pair includes an input spur gear and an output spur gear that mesh with each other; the driving bevel gear is installed on the output shaft of the brushless DC motor; the harmonic reducer is fixedly installed on the housing base; the driven bevel gear is installed on the input shaft of the harmonic reducer; the input spur gear is installed on the output shaft of the harmonic reducer; first and second bearings are sleeved at both ends of the output spur gear, the outer ring of the first bearing is installed on the housing base, and the outer ring of the second bearing is installed on the front housing.

[0008] Preferably, a rectangular hole is provided on the output spur gear for connecting with the steering shaft of the servo.

[0009] Preferably, alignment grooves are respectively provided on the input spur gear and the output spur gear.

[0010] Preferably, the input spur gear and the output shaft of the harmonic reducer are fixedly locked by a locking screw and a retaining ring; the locking screw passes through the retaining ring and is screwed on the end face of the output shaft of the harmonic reducer; the retaining ring presses against the input spur gear.

[0011] Preferably, mounting holes are provided on the input spur gear, and a pair of mutually parallel rotation limiting surfaces are provided on the mounting holes; a pair of mutually parallel flat surfaces are provided on the output shaft of the harmonic reducer; the output shaft of the harmonic reducer is inserted into the mounting hole of the input spur gear, and the rotation limiting surfaces are mutually attached to the flat surfaces.

[0012] Preferably, both the input spur gear and the output spur gear are non-full gear structures, 10 teeth are retained on the input spur gear, and 5 teeth are retained on the output spur gear; a plurality of relief holes are respectively provided on the input spur gear and the output spur gear.

[0013] Preferably, a retaining bar is integrally formed on the outer peripheral surface of the input spur gear; a first baffle and a second baffle are provided on the inner cavity bottom wall of the housing base for forming a blocking limit for the retaining bar; and the included angle α between the first baffle and the second baffle is 60°; when the input spur gear is in the zero position state, the first baffle and the second baffle are symmetrically distributed on both sides of the retaining bar; the reduction ratio between the input spur gear and the output spur gear is 2.

[0014] Preferably, a potentiometer is installed on the rear housing by screws; the central shaft of the driven bevel gear is connected to the potentiometer; the potentiometer is used to monitor the rotation angle of the driven bevel gear.

[0015] Preferably, a brake is installed at the rear end of the brushless DC motor, and the brake is used for power-off self-locking of the brushless DC motor.

[0016] Due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0017] (1) In the present invention, by using a bevel gear transmission pair, a harmonic reducer, and a spur gear transmission pair for speed reduction, since the harmonic reducer has a large reduction ratio range, it is beneficial to meet the requirements of miniaturization and lightweight of the electric actuator.

[0018] (2) In the present invention, a brushless DC motor is used for driving, and a brake is installed at the end of the brushless DC motor to perform power-off self-locking on the brushless DC motor, thereby realizing the power-off self-locking function of the electric steering gear.

[0019] (3) In the present invention, both the input spur gear and the output spur gear are designed as non-full gear structures, that is, 10 teeth are retained on the input spur gear, 5 teeth are retained on the output spur gear, and a plurality of relief holes are respectively provided on the input spur gear and the output spur gear, achieving the purpose of reducing the volume and weight of the electric steering gear, and further facilitating the realization of the requirements of miniaturization and light weight of the electric steering gear.

[0020] (4) In the present invention, a limiting structure is formed by using the retaining strip on the outer peripheral surface of the input spur gear and the first baffle and the second baffle in the housing base, so as to mechanically limit the output steering angle of the electric steering gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0022] Figure 1 It is a general structure cross-sectional view of the electric steering gear provided by the present invention;

[0023] Figure 2 It is an exploded view of the spur gear transmission pair in the present invention;

[0024] Figure 3 It is Figure 2 an enlarged view of part A in

[0025] Figure 4 It is a front view of the electric steering gear provided by the present invention after removing the front housing.

[0026] Explanation of the reference numerals in the drawings: 1. Brushless DC motor; 2. Brake; 3. Plug; 4. Motor wire; 5. Cable; 6. Anti-rotation pin; 7. Driving bevel gear; 8. Driven bevel gear; 9. Potentiometer; 10. Screw; 11. Rear housing; 12. Harmonic reducer; 13. Housing base; 13a. First baffle; 13b. Second baffle; 14. First bearing; 15. Output spur gear; 16. Second bearing; 17. Bushing; 18. Front housing; 19. Input spur gear; 19a. Rotation limiting surface; 19b. Retaining strip; 20. Retaining ring; 21. Locking screw; 22. Alignment groove; 23. Relief hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0030] Combined with Figures 1 to 4 As shown, it is a specific embodiment of a small high-reduction-ratio electric steering gear provided by the present invention. The electric steering gear includes a housing base 13, and a rear housing 11 and a front housing 18 mounted on the housing base 13; a harmonic reducer 12 and a bevel gear transmission pair are arranged in the cavity formed by the housing base 13 and the rear housing 11; a spur gear transmission pair is arranged in the cavity formed by the housing base 13 and the front housing 18; a brushless DC motor 1 is mounted on the outer wall of the rear housing 11, and the power of the brushless DC motor 1 is sequentially transmitted to the spur gear transmission pair through the bevel gear transmission pair and the harmonic reducer 12.

[0031] Combined with Figure 1 and Figure 2As shown in the figure, the bevel gear transmission pair includes a driving bevel gear 7 and a driven bevel gear 8 that mesh with each other; the spur gear transmission pair includes an input spur gear 19 and an output spur gear 15 that mesh with each other; the driving bevel gear 7 is installed on the output shaft of the brushless DC motor 1, and an anti-rotation pin 6 is installed between the driving bevel gear 7 and the output shaft of the brushless DC motor 1 to prevent relative rotation between the two. The harmonic reducer 12 is fixedly installed on the housing base 13; the driven bevel gear 8 is installed on the input shaft of the harmonic reducer 12; the input spur gear 19 is installed on the output shaft of the harmonic reducer 12; a first bearing 14 and a second bearing 16 are sleeved at both ends of the output spur gear 15. The outer ring of the first bearing 14 is installed on the housing base 13, and the outer ring of the second bearing 16 is installed on the front housing 18. A bushing 17 is installed between the outer ring of the second bearing 16 and the front housing 18. A rectangular hole 15a is provided on the output spur gear 15 for connecting with the steering shaft of the steering gear.

[0032] With the above structure, during use, the steering shaft of the steering gear is inserted into the rectangular hole 15a of the output spur gear 15. The brushless DC motor 1 outputs power, which is transmitted to the driving bevel gear 7 through its output shaft. Since the driving bevel gear 7 meshes with the driven bevel gear 8, the power is transmitted to the driven bevel gear 8. The driven bevel gear 8 is connected to the harmonic reducer 12. The power is decelerated and torque-increased through the bevel gear transmission pair and the harmonic reducer 12, and the power is output to the input spur gear 19, and then can be transmitted to the steering shaft of the steering gear through the output spur gear 15.

[0033] In this embodiment, by adopting the bevel gear transmission pair, the harmonic reducer 12, and the spur gear transmission pair for transmission, the total reduction ratio can reach 707, which can meet the requirement of a large reduction ratio.

[0034] To ensure the transmission accuracy, it is required to ensure the machining accuracy of the input spur gear 19 and the output spur gear 15 to reduce the gear backlash between the input spur gear 19 and the output spur gear 15.

[0035] Combined with Figure 3 As shown in the figure, alignment grooves 22 are respectively provided on the input spur gear 19 and the output spur gear 15. During the assembly process, alignment is carried out by using the alignment grooves 22 to reduce the installation error and improve the transmission accuracy.

[0036] Combined with Figure 1 and Figure 2As shown, the input spur gear 19 is fixedly locked to the output shaft of the harmonic reducer 12 by a locking screw 21 and a retaining ring 20. The locking screw 21 passes through the retaining ring 20 and is screwed onto the end face of the output shaft of the harmonic reducer 12. The retaining ring 20 presses against the input spur gear 19. By using the structure in which the retaining ring 20 and the locking screw 21 cooperate, the input spur gear 19 can be fastened to the output shaft of the harmonic reducer 12. In addition, mounting holes are provided on the input spur gear 19, and a pair of mutually parallel rotational limiting surfaces 19a are provided on the mounting holes. A pair of mutually parallel flat surfaces 12a are provided on the output shaft of the harmonic reducer 12. The output shaft of the harmonic reducer 12 is inserted into the mounting hole of the input spur gear 19, and the rotational limiting surface 19a and the flat surface 12a are mutually attached, which can effectively prevent relative rotation between the output shaft of the harmonic reducer 12 and the input spur gear 19.

[0037] Combined with Figure 2 As shown, both the input spur gear 19 and the output spur gear 15 are non-full gear structures. 10 teeth are retained on the input spur gear 19, and 5 teeth are retained on the output spur gear 15. A plurality of relief holes 23 are respectively provided on the input spur gear 19 and the output spur gear 15. By adopting the above structure, the purpose of reducing the volume and weight is achieved, which further facilitates meeting the requirements of miniaturization and light weight of the electric actuator.

[0038] Combined with Figure 2 and Figure 4 As shown, a retaining bar 19b is integrally formed on the outer peripheral surface of the input spur gear 19. A first baffle 13a and a second baffle 13b are provided on the inner cavity bottom wall of the housing base 13 to form a blocking limit for the retaining bar 19b. The included angle α between the first baffle 13a and the second baffle 13b is 60°. When the input spur gear 19 is in the zero position state, the first baffle 13a and the second baffle 13b are symmetrically distributed on both sides of the retaining bar 19b. The reduction ratio between the input spur gear 19 and the output spur gear 15 is 2. By adopting the above structure, the rotation angle of the output spur gear 15 can be limited to plus or minus 15°, which plays a role in mechanically limiting the output rudder angle of the electric actuator. During the working process, by energizing the brushless DC motor 1 and controlling its forward and reverse rotation, the output power is transmitted to the spur gear transmission pair through the bevel gear transmission pair and the harmonic reducer 12, thereby causing the output spur gear 15 to swing within an angle of plus or minus 15°.

[0039] Combined with Figure 1As shown in the figure, a potentiometer 9 is installed on the rear housing 11 by screws 10; the central axis of the driven bevel gear 8 is connected to the potentiometer 9; the potentiometer 9 is used to monitor the rotation angle of the driven bevel gear 8. Further, the cable 5 of the potentiometer 9 and the motor wire 4 of the brushless DC motor 1 are both connected to the plug 3. The plug 3 is connected to a power socket board to supply power to the potentiometer 9 and the brushless DC motor 1.

[0040] Combined with Figure 1 As shown in the figure, a brake 2 is installed at the rear end of the brushless DC motor 1, and the brake 2 is used to perform power-off self-locking on the brushless DC motor 1 to achieve control stability.

[0041] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A small electric steering gear with a large reduction ratio, characterized in that, It includes a housing base (13), a rear housing (11) and a front housing (18) mounted on the housing base (13); a harmonic reducer (12) and a bevel gear pair are arranged in the cavity formed by the housing base (13) and the rear housing (11); a spur gear pair is arranged in the cavity formed by the housing base (13) and the front housing (18); a brushless DC motor (1) is mounted on the outer wall of the rear housing (11), and the power of the brushless DC motor (1) is transmitted to the spur gear pair through the bevel gear pair and the harmonic reducer (12) in sequence.

2. The small high-reduction-ratio electric steering gear according to claim 1, characterized in that, The bevel gear pair includes a driving bevel gear (7) and a driven bevel gear (8) that mesh with each other; the spur gear pair includes an input spur gear (19) and an output spur gear (15) that mesh with each other. The driving bevel gear (7) is mounted on the output shaft of the brushless DC motor (1); the harmonic reducer (12) is fixedly mounted on the housing base (13); the driven bevel gear (8) is mounted on the input shaft of the harmonic reducer (12). The input spur gear (19) is mounted on the output shaft of the harmonic reducer (12); a first bearing (14) and a second bearing (16) are sleeved at both ends of the output spur gear (15), the outer ring of the first bearing (14) is mounted on the housing base (13), and the outer ring of the second bearing (16) is mounted on the front housing (18).

3. The small electric steering gear with large reduction ratio according to claim 2, characterized in that A rectangular hole (15a) is provided on the output spur gear (15) for connecting with the steering shaft of the steering gear.

4. A small electric steering gear with a large reduction ratio according to claim 2, characterized in that Alignment grooves (22) are respectively provided on the input spur gear (19) and the output spur gear (15).

5. The small high-reduction-ratio electric steering gear according to claim 2, characterized in that The input spur gear (19) and the output shaft of the harmonic reducer (12) are fixedly locked through a locking screw (21) and a retaining ring (20); the locking screw (21) passes through the retaining ring (20) and is screwed on the end face of the output shaft of the harmonic reducer (12); the retaining ring (20) presses against the input spur gear (19).

6. The small high reduction ratio electric steering gear according to claim 2, characterized in that, An installation hole is provided on the input spur gear (19), and a pair of mutually parallel rotation limiting surfaces (19a) are provided on the installation hole; a pair of mutually parallel flat surfaces (12a) are provided on the output shaft of the harmonic reducer (12); the output shaft of the harmonic reducer (12) is inserted into the installation hole of the input spur gear (19), and the rotation limiting surface (19a) is in mutual fit with the flat surface (12a).

7. The small electric steering gear with large reduction ratio according to claim 2, characterized in that, Both the input spur gear (19) and the output spur gear (15) are non-full gear structures, 10 teeth are retained on the input spur gear (19), and 5 teeth are retained on the output spur gear (15); a plurality of relief holes (23) are respectively provided on the input spur gear (19) and the output spur gear (15).

8. The small high reduction ratio electric steering gear according to claim 2, characterized in that, A retaining bar (19b) is integrally formed on the outer peripheral surface of the input spur gear (19); a first baffle (13a) and a second baffle (13b) are provided on the inner cavity bottom wall of the housing base (13) to form a blocking limit for the retaining bar (19b); and the included angle α between the first baffle (13a) and the second baffle (13b) is 60°; when the input spur gear (19) is in the zero position state, the first baffle (13a) and the second baffle (13b) are symmetrically distributed on both sides of the retaining bar (19b); the reduction ratio between the input spur gear (19) and the output spur gear (15) is 2.

9. The small high reduction ratio electric steering gear according to claim 2, wherein, A potentiometer (9) is installed on the rear housing (11) by screws (10); the central axis of the driven bevel gear (8) is connected to the potentiometer (9); the potentiometer (9) is used to monitor the rotation angle of the driven bevel gear (8).

10. A small high reduction ratio electric steering gear as claimed in claim 1, characterized in that, A brake (2) is installed at the rear end of the brushless DC motor (1), and the brake (2) is used for power-off self-locking of the brushless DC motor (1).

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